Driving system for ships stabilizers

ABSTRACT

An hydraulic-driving system for a nonretractable fin of a ships&#39;&#39; stabilizers includes a housing joined to the inside of the ship&#39;&#39;s hull with bearings for the fin shaft and hydraulic-driving means. The housing includes a space for a charge of hydraulic oil and the housing wall facing the fin is arranged to be bathed by sea water so as to cool the oil.

United States Patent Inventor Heinz-Gunter Ehluss Tornesch Holstein, Germany App]. No. 1,641 Filed Jan. 9, 1970 Patented Nov. 9, 1971 Assignee Howaldtswerke-Deutsche Werft Aktiengesellschafl Hamburg Und Kiel, Hamburg, Germany DRIVING SYSTEM FOR SHIPS STABILIZERS 5 Claims, 2 Drawing Figs.

11.8. CI 114/126 Int. Cl B631 39 9 B63b 43/06 Field oISeareh 114/122. 126

[56] References Cited UNITED STATES PATENTS 3,020,869 2/1962 Beach 114/126 3,172,389 3/1965 Turin 114/126 Primary Examiner-Trygve M. Blix Attorney-Stevens, Davis, Miller & Mosher ABSTRACT: An hydraulic-driving system for a nonretractable fin of a ships stabilizers includes a housing joined to the inside of the ship's hull with bearings for the fin shaft and hydraulic-driving means. The housing includes a space for a charge of hydraulic oil and the housing wall facing the fin is arranged to be bathed by sea water so as to cool the oil.

PATENTEDNHV 9197! 3 618 553 SHEET 1 0F 2 PATENTED MIN 9 I97! SHEET 2 BF 2 DRIVING SYSTEM FOR SHIPS STABILIZERS BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a compact hydraulic driving system for nonretractable fins of shipsstabilizers having a housing firmly joined to the ships hull, which housing comprises bearings for the fin shaft and the hydraulic fin entraining element situated within its internal space.

2. Description of the Prior Art A system is known for stabilization of ships by means of retractable fins or blades, in which hydraulic motors working with oil for retraction and rotation of the fins, as well as pressure tanks for operation of the retracting motor, are situated in a housing which also receives the bearings of the blade or fin shaft and for its part is displaceable in a fin compartment formed as a hollow cylinder. The pump and oil-cooling systems of the circuit are not situated within the housing, and must therefore be stowed outside the housing.

The idea of concentrating the impelling and control elements for the fins at one point as far as possible, has also been employed. A rotary-blade-driving system has thus been suggested for the rudder and the fins of ships, which around the case of a vane-type motor has a horizontal platform firmly joined to the case, on which are stowed all the other components of the hydraulic system.

ln another known stabilizing system for ships, comprising a nonretractable fin pivotable around its longitudinal axis, drive is transmitted to the fin by a hydraulic motor which has an end plate fastened on a tubular housing arranged on the side of the ship and surrounding the part of the fin shaft extending into the ship, whereof the inside is sealed off from sea water and at the same time contains the bearings of the fin shaft; and in which a stationary housing arranged on the end plate and surrounding the rotor of the motor is situated in the internal cavity of the hollow fin shaft.

The disadvantages of this fin or blade stabilizer in particular reside in that considerable space is required in the the stabilizer hold or in another hold of the ship, for stowage of the other assemblies required, such as a hydraulic oil tank, hydraulic oil pump with a motor, the control unit and the lubricating oil assembly.

Beyond this, the assemblies must be connected in situ with the actual fin-driving system by means of pipes, which brings the risk of contamination of the hydraulic-oil system. Longer pipes moreover mean power losses owing to increased liquid friction. To prevent any heating of the hydraulic oil beyond 50 C. as far as possible, it is necessary to have either oil tanks of relatively great capacity, or auxiliary oil-cooling systems such as tubular coolers, as well as an electric motor and a pump for oil circulation.

To prevent these shortcomings, the invention is based on the problem of creating a compact-driving system for finned or bladed ships stabilizers, which requires little space and in which only a relatively small quantity of hydraulic oil is employed, and which may be cooled without bulky coolers in such manner that the temperature does not exceed the permissible limit (50C).

SUMMARY BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 diagrammatically shows a longitudinal section through a compact driving system according to the invention, and

FIG. 2 diagrammatically shows a system employing a drive for fins of ships stabilizers.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the housing 1 is rotatably arranged a fin shaft 2 of a fin 3. An outer bearing 4 which is preceded by a sealing system 5 facing towards the fin 3 and comprising a barrier oil chamber 6, is carried by an extemal-housing wall 7, the latter forming a cooling chamber 9 conjointly with a housing case 8 fastened on the side of the ship. On the inner side of the housing wall 7 are situated cooling fins 10, 11 which act as complementary reinforcements conjointly with the outer bearing 4 as well as with the housing wall 7, and are firmly joined to the housing case 8. An inner bearing 12 is arranged in an inner housing cover 13 which, for its part, is bolted to the housing I. A hydraulic vane-type driving system 14 comprising vanes 14a is rigidly coupled between the outer bearing 4 and the inner bearing 12 within the internal space la of the housing I, and a device 15 is incorporated for holding the stabilizer fin 3 with the shaft 2 in the neutral position, which keeps the fin 3 in the neutral position when not in operation.

A control assembly comprising a pump 16, an electric motor 17 and a pulse control mechanism 18 situated between the two, is inserted through an opening 19 of the housing cover 13 into the housing I and bolted on by means of a flange 20. The electric motor 17 concomitantly remains outside the housing 1.

After fitting the parts described in the foregoing, the housing 1 is filled with hydraulic oil 21, so that it is also employed as a hydraulic oil tank at the same time. Cooling the hydraulic oil 21 to a required temperature (below 50 C.) is performed by the sea water continually renewed in the cooling chamber 9 by the reciprocating motion of the stabilizer fin 3, the sea water acting on the hydraulic oil 21 through the housing wall 7 and the cooling fins 10, 11.

Other component assemblies and separate parts, such as remote-indication system, control unit, hydraulic block, hydraulic reservoir, etc., are commonly secured externally on the housing 1 but have not been illustrated in detail in the embodiment of FIG. 1.

In FIG. 2, which discloses a diagram of a driving system for the fins of ships stabilizers, 24 marks a gyroscope or the like which supplies a control pulse converted into a mechanicalsetting value (servocontrol) in a control unit 25. This mechanical setting value is transmitted to the pulse control mechanism 18 which is in communication through a pipe with a hydraulic reservoir 26. The fin-driving mechanism 14, is in communication with the pulse control mechanism 18 through an outgoing pipe and a return pipe.

The electric motor 17 transmits drive at constant speed to the rotary pump 16 and the rotating part of the pulse control mechanism 18 containing an external sleeve element which is displaceably arranged on the inner rotating part and which is displaced back and forth on the rotating part as a function of the pulse generated through the setting value generator 25 on the basis of the motion of the gyroscope 24. In accordance with the displacement of the outer part of the pulse control mechanism 18, oil is delivered from the pressurized hydraulic reservoir 26 into the hydraulic driving system 14 to pivot the fin 3 in one direction or the other. The direction and speed of the displacement of the fin is controlled thereby.

Because of the rotation of the electric motor 17, oil is constantly delivered from the housing 1, through the pump 16, to the hydraulic tank 26 which, for its part and as a function of the position of the outer displaceable part of the pulse control mechanism 18, delivers oil under pressure to the fin-driving system 14, 140, the delivery volume of the pump 16 being increased to a multiplied value. The oil flowing back out of this fin-pivoting drive mechanism 14, 14a, is returned to the housing 1 again through the pulse control mechanism 18.

It is essential that the tin 3 be held effectively in a neutral position, when it is not in operation. To this end. the device 15 is incorporated to hold the stabilizing fin 3 in the neutral position. This device may be of known kind, for example it may contain springs acting ambilaterally on a flange which is fastened on the fin shaft 2.

The advantages accruing from the invention specifically consist in that by virtue of the arrangement of its component assemblies or individual components within its internal space or on the outside of the housing, the compact driving system represents a structural unit requiring particularly little space, which is assembled fully in the works prior to installation, and is then merely bolted on the pedestal or the like 22 provided for this purpose on board of the corresponding ship, prior to being welded to the side 23 of the ship.

Another advantage of the compact driving system resides in that it eliminates the piping systems required in the case of the known hydraulic fin-driving systems, and thus the risk of particles of dirt penetrating into the hydraulic system.

Analogously, and by virtue of employing the housing as a hydraulic oil tank, it is no longer necessary to take measures to protect the hydraulic mechanisms situated in the inner cavity against losses of oil by leakage, so that the return flow of oil can emerge direct from the pulse control mechanism for example, and all the moving parts situated within the housing do not require any additional lubrication. The oil contained in the housing is moreover constantly kept at the permissible temperatures of less than 50 C., in advantageous manner by natural circulation along the housing wall externally bathed by sea water. Complementarily, the oil charge performs a definite degree of noise damping and a mechanical damping action on the surges otherwise caused by parts displaced suddenly within the oil.

lclaim:

l. A compact hydraulic-driving system for a nonretractable fin of a ship's stabilizer, comprising a closed housing firmly joined to the hull of the ship and having therein bearings, fin shaft one end of which is mounted in said bearings and the other end of which is attached to said fin, a hydraulic-drive system connected to said shaft for driving the fin, said system comprising a hydraulic pump, a control mechanism, and an electric motor mounted outside said housing driving said pump, a charge of hydraulic oil substantially filling the remaining volume of said housing, the housing wall facing towards the nonretractable fin being bathed by the sea water and serving for cooling the charge of hydraulic oil.

2. A compact hydraulic-driving system according to claim I, further comprising cooling fins for cooling the charge of hydraulic oil in the internal space of the housing, said cooling fins being situated on the housing wall which faces towards the nonretractable fin.

3. A compact hydraulic-driving system according to claim 1, further comprising a cooling chamber for cooling the charge of hydraulic oil, which chamber is delimited by the outer wall of the housing which faces towards the nonretractable fin,

4. A compact hydraulic-driving system according to claim 3, wherein the wall of the housing facing towards the fin is recessed into the ship s hull to form the cooling chamber.

5. A compact hydraulic-driving system according to claim 1, wherein said bearings comprise an outer bearing receiving the fin shaft and arranged in the housing wall which faces towards the fin and further comprising a sealing system comprising a barrier oil chamber contained in said outer bearing, 

1. A compact hydraulic-driving system for a nonretractable fin of a ship''s stabilizer, comprising a closed housing firmly joined to the hull of the ship and having therein bearings, fin shaft one end of which is mounted in said bearings and the other end of which is attached to said fin, a hydraulic-drive system connected to said shaft for driving the fin, said system comprising a hydraulic pump, a control mechanism, and an electric motor mounted outside said housing driving said pump, a charge of hydraulic oil substantially filling the remaining volume of said housing, the housing wall facing towards the nonretractable fin being bathed by the sea water and serving for cooling the charge of hydraulic oil.
 2. A compact hydraulic-driving system according to claim 1, further comprising cooling fins for cooling the charge of hydraulic oil in the internal space of the housing, said cooling fins being situated on the housing wall which faces towards the nonretractable fin.
 3. A compact hydraulic-driving system according to claim 1, further comprising a cooling chamber for cooling the charge of hydraulic oil, which chamber is delimited by the outer wall of the housing which faces towards the nonretractable fin.
 4. A compact hydraulic-driving system according to claim 3, wherein the wall of the housing facing towards the fin is recessed into the ship''s hull to form the cooling chamber.
 5. A compact hydraulic-driving system according to claim 1, wherein said bearings comprise an outer bearing receiving the fin shaft and arranged in the housing wall which faces towards the fin and further comprising a sealing system comprising a barrier oil chamber contained in said outer bearing. 